This section provides background information related to the present disclosure which is not necessarily prior art.
Automatic sprinklers are well known and have long been used in fire extinguishing systems. Typically, automatic sprinkler assemblies include a sprinkler body which includes an inlet for connecting to a pressurized supply of water or other fire extinguishing fluid, an outlet opening, and a deflector which is mounted spaced from the outlet opening of the sprinkler body. The deflector disperses and directs the water in an optimum pattern when the water is discharged through the outlet opening. In one common form, the deflector is mounted in a fixed position and spaced from the outlet opening by a frame. The frame includes a pair of arms, which attach to either side of the sprinkler body, and aligns the deflector with the path of the water when it is discharged through the outlet opening. The outlet opening is normally closed by a closure seal which is held in place typically by a trigger element, such as a glass bulb or a fusible link element. The trigger element extends between the seal and the frame and is usually held in place by a set screw or the like.
Other forms of sprinkler assemblies include flush sprinkler assemblies. Flush sprinkler assemblies include a housing and a deflector which is recessed within the housing. The deflector is movably mounted to the sprinkler body by a pair of guide members and moves between a closed position in which the deflector is recessed within the housing and an extended position wherein the deflector projects from the housing and is spaced from the outlet opening of the sprinkler body. Since the deflector is supported only by two guide members, the deflector can experience instability or rotation about the axis extending between the two guide members. Similar to a fixed sprinkler assembly, a flush sprinkler assembly includes a thermally responsive trigger mechanism and a fluid seal. In a flush sprinkler, the fluid seal is positioned within the interior of the sprinkler body and is maintained in a closed position by a pair of pins or actuators. The pins are inwardly biased by the trigger mechanism. Thus, under normal operating conditions, the trigger mechanism prohibits fluid flow from the outlet of sprinkler body. When the temperature rises to a preselected value, the trigger mechanism, which is normally a fusible link, separates permitting the pins to move in an outward direction under the pressure of the water. With the separation of the fusible link, the pressure in the water supply line pushes the fluid seal away from the outlet opening and the deflector to its outward position thereby enabling the water to travel through the sprinkler body and to be dispersed by the deflector.
In side wall mounted sprinklers, however, the ejection of the trigger assembly may slow the release of the deflector from within the housing of the flush sprinkler assembly. Additionally, the orientation of the assembly causes the pressurized water to disperse in a horizontal direction. While attempts have been made to redirect the flow of the water downwardly by adding a blade to the deflector, heretofore these side wall sprinklers have not produced an optimal spray pattern. Nor are they suitable for flush mounted arrangements since they do not permit the deflector to be fully recessed within the sprinkler base. Consequently, there is a need for a flush side wall sprinkler assembly which offers improved ejection of the trigger assembly from the sprinkler assembly when the trigger is activated. Furthermore, there is a need for an automatic side wall sprinkler assembly which exhibits an optimized spray pattern.
It is also recognized that significant energy losses occur at the sprinkler assemblies where the fluid is dispersed. As discussed herein, conventional sprinkler assemblies often include a frame having a pair of arms, which attach to either side of the sprinkler body, and aligns the deflector with the path of the water when it is discharged through the outlet opening. The arms are often joined at their distal ends by a boss, which is used to mount the deflector to the arms. Pendent sprinklers and upright sprinklers typically include deflectors with a solid central portion and a plurality of tines that extend radially outwardly from the central portion for dispersing the fluid as it flows across the solid central portion, which is mounted to the boss and typically aligned with the discharge opening of the base. Sidewall sprinklers typically include a deflector, also with a solid central portion with tines extending from the central portion and a blade that is positioned above the central portion to direct the fluid that flows above the central portion outwardly and downwardly. In each case, when the fluid flows from the discharge opening of the base the fluid impinges on the boss and on the central portion of the deflector. The boss and deflector disperse the fluid radially outward, and the fluid is thereafter further dispersed by the tines, and in the case of the sidewall sprinklers also by the blade. This results in a sizeable energy or head loss in the fluid at the sprinkler assembly. Significant savings can be realized for a sprinkler system if the supply pressure to the sprinkler assembly can be reduced. As would be understood by those skilled in the art, where the supply pressure to the sprinkler assemblies of a system can be reduced, the size of the piping delivering the fluid to the sprinkler assemblies can be reduced and/or the size of the system pump can be downsized. If comparable performance of a sprinkler assembly can be provided at a lower pressure for any given system, the need for a pump might even be avoided. Any of these modifications could provide significant savings in the installation cost of a fire protection system. Accordingly, a sprinkler assembly, that combines the benefits of a concealed sidewall arrangement, that can disperse fluid with a reduced head loss may reduce the required pressure at the sprinkler assembly and, hence, provide cost savings for the installation of a fire protection system incorporating such sprinkler assemblies.